-----Original Message----- From: Michael Van Canneyt <[EMAIL PROTECTED]> To: FPC developers' list <fpc-devel@lists.freepascal.org> Date: Fri, 6 Oct 2006 22:01:55 +0200 (CEST) Subject: Re: [fpc-devel] rtti, arrays and performance
> Did you see a change in performance ? Can you give an order of magnitude ? > For me Shark profiler shows that 60%-70% of time spent in fpc_finalize (this is on intel core duo, havn't measured on powerpc). After change it shown just a few percents (I do not remember exactly, and it's a little bit hard to measure exactly because this block is performd in a few seconds now). But it's just a mine specific case. I use dynamic arrays heavily there, too much, it would be better to use getmem there and then type cast it as pointer to array. Generally speaking I think that it's not a significant optimization for most of applications. Just it was easer for me to tweak rtl than to change my code :). But anyway - if I have array of integer with a hundreds thousand items call to finalize each item is not really good I think. What if user has record with array inside, and that record has some dynamic variable? as I understand fpc_finalize will try to finalize array too... And as I understand dynamic arrays always finalizing their items. > > I think it may be indeed a better idea to see whether the compiler can set a > flag in the type info: > > If we change TTypeInfo to > > TTypeInfo = record > Kind : TTypeKind; > Finalize : Boolean; > Name : ShortString; > // here the type data follows as TTypeData record > end; > > Then there is no need for a recursive loop (the compiler has already done > that...); > Only the Finalize field needs to be retrieved. Putting this field in the > middle will > make sure 99,9% of all existing code will still work. > I don't know is this good - perhaps to not break other's code such attribute can be placed before type info record (at offset -1 or -4 from typeinfo pointer:)),so, if somebody relies on current typeinfo format his code will be not broken? _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
